There is known a jack in which one jack case houses so-called jack contact pieces adapted to come in contact with the conductor of a plug and to be maintained as contacted therewith. The jack case also houses contact switches of other systems independent from the jack contact pieces, these contact switches adapted to be closed/opened according to the insertion/removal of the plug. In such a jack, the movable-side contact pieces constituting the contact switches are generally pressed indirectly by the plug conductor through a separator made of an insulating material. These separators are conventionally secured directly to the movable-side contact pieces by means of press-insertion, fitting or welding. Therefore, certain portions of the movable-side contact pieces become inoperative, so that the resiliency of the contact pieces cannot be efficiently utilized.
In such a jack, the amount of displacement of the separator, at the time the plug is inserted, is relatively small and therefore the amount of stroke sufficient to open and close the contact switches cannot be provided. This presents a problem in that a switching operation of the contact switches is not securely performed.